Tire mold



sept. 15, 1925, 1,554,018

T. MIDGLEY TIRE MOLD Filed Aug. 31, 1925 I N VEN TOR.

AT ORNEY.

Patented Sept. 15, 1925.

UNITED STATES OFFICE. I

THOMAS MIDGLEY, OF HAMPDEN, MASSACHUSETTS, ASSIGNR T THE FISK RUBBERCOMIBANY, 0F CHICOPEE FALLS, MASSACHUSETTS, A CORPORATION 0F MASSACHU-SETTS.

l Tran Munn.

application niet August ai, ma? sensi ne. seater.

To ZZ whom t may concern.'

Be it known thatl, THOMAS MIDGLEY, a citizen of the United States ofAmerica, residing at Hampden, in the county of Hampt den and State ofMassachusetts, have invented certain new and useful Improvements 'in aTire Mold, of which the following is a specification.

The present invention relates to tire molds adapted to be .constructedout of sheet metal and particularly intended for use in thevulcanization of automobile tire casings under internal fluid pressure.This invention is in the nature of a modification 'of the molds shownand described in my copending applications Serial Nos. 659,813 and660,296, filed Aug. 28, 1923, and Aug. 31, 1923, re-- spectively. Theinvention will now be described in connect-ion with the accompanyingdrawings, in whichf y Fig. 1 is a sectional perspectivel view of a moldembodying the invention;

Fig. 2 is a sectional view with the parts se arated; 2t ig. 3 is adetail, artly broken away,

looking on line 3-3 o Fig. 1; and

T Fig. 4 is a detail looking on line 1 -d of 'lhe mold comprises sideplates 10 suitably shaped to the transverse curvature of the tireto beproduced and provided with shoulder Vportions 11 forming recesses forthe reception of other parts to be described. Lying in these recesses,and extending so as to meet at the central plane ofthe assembled mold,are. cover plates 12 defining, when the mold is being used, theoutermost surface of the tire bein molded. Also lying within therecesses, but terminating short of the central plane of the mold so asto form together with the cover plates a central recess which will forma circumferential rib 14 upon the tire, are tread forming strips 13,preferably perforated and treated in accordance with the disclosure inmy prior application No. 659,813 referred to above so as to form moldingcavities terminating at cover plates 12 and designed to produce thedesired molded tread hattern on the tire. The cover plates an treadforming strips are preferably secured permanently in the recess intheside plates, as by spot welding, so that the two mold halves willfunction as units.

rThe side plates entend beyond the recesses substantially parallel tothe plane of the mold so as to form flanges 15 which, as is shown inFig. 1, are parallel to each other and capable of being used asabutments against whicha prying tool may be applied to assist inseparating the molds after the vulcanization of a tire therein. ratelyregister theA mold halves together, so that the tread pattern producedon the tire casing will be symmetrical, interengaging plates'l and 17(Fig. fl) are attached respectively to lthe 'two cover plates.Preferably a series of these interengaging plates are provided aroundthe periphery of the mold. v

The inner portions of the side plates are bent toward the central planeof the mold, as indicated at 18, nnderlying the bead portions 19 of thetire casing 20 and referably terminating1 short of the centra plane ofthe mold. Secured to the flanges 18, preferably by l spot welding, areannular plates 21 having danges 22 thereon serving as supports for theseveral molds when these are stacked in vertical formation in a heater.These plates bridge the gap between the anges 18 so as to receive thebase portion To accu- 23of the annular fluid bag 24 by which i pressureis transmitted to the tire casing during vulcanization. rlFhe stem 25 ofthis bag passes through suitable notches in the .plates 21, as indicatedin Fig. 1. ln order to provide drainageof any condensed moisture, aseries of holes 26 are preferably provided in plates 21 near thejuncture point of these plates with the side plates 10. l

The method of producing the tread design in this mold is similar to thatset forth in my copending application No. 659,813 referred to exceptthat instead of forming the apertures, which are to, constitute themolding cavities, directly in the side plates these are formed in thetread forming strips 13. 'lin this respect the mold is similar to thatdescribed in't my copending application Serial No. 660,296, ledconcurrently herewith. ltf desired',l a continuation of the mold design.mayr beyllfformed at 27 on the side plates 10. f' f Having thus'described my invention, 1 claim:

1. A mold adapted for use in the vulcanization of tire casings andconstructed'in mating annular halves, each half comprising desired treaddesign to the tire, saidstrip terminating short of the central plane ofthe assembled mold, a cover plate overlying the tread forming strip andextending to the central plane of the mold, said strip and cover platelying in a -depression in'the` side plate and being permanently securedthereto; and interfitting members secured respectively to the two moldhalves and adapted to cause proper registration thereof when assembled.

' 2. A mold adapted for use in the vulcanization of tire casings andconstructed in mating annular halves, each halt` compris` ing a sideplate curved; to give the desired form to a side portion of the tire,and extending outwardly in a flange serving together with a similarflange on the other mold half to assist in the separation of the moldhalves, a tread forming strip shaped to impart the desired tread designto the tire, said strip terminating short of the central plane of theassembled mold, a cover plate overlying the tread forming strip andextending to the central plane of the mold, said strip and cover platelying in a depression in the side plate and being permanentlysecuredthereto.

3. A mold adapt dfor use in the vulcanization of tire casings andconstructed in vmating annular halves, each half comprising a side platecurved to give the desired form to a side portion of the tire, a `treadforming strip shaped to impart the desired-tread design to the tire,said strip terminating short of the central plane .of the assembledmold, a lcover plate overlying the tread forming strip and extending tothe central l plane of the mold, said strip and cover plate

